Properties of Ag-doped Bi-Sb alloys as thermoelectric conversion materials for solid state refrigeration

Abstract

The energy conversion properties of Bi-Sb system thermoelectric materials doped by Ag was investigated. Bi₈₅Sb_15-xAg_x (x=0, 1, 2, 3, 4) alloys with Ag substitution for Sb were synthesized by mechanical alloying and then pressed under 5 GPa at 523 K for 30 min. The phase structure of the alloys was characterized by X-ray diffraction. The electric conductivities and the seebeck coefficients were measured at the temperature range of 80-300 K. The results reveal that the electric conductivities of the Ag-doped Bi-Sb alloys are highly improved. The power factor of Bi₈₅Sb₁₄Ag₁ reaches a maximum value of 2.98×10^-3 W/(K²•m) at 255 K, which is about three times that of the un-doped sample Bi₈₅Sb₁₅ at the same temperature.

Keywords

thermoelectric conversion materials / high-pressure sintering / thermoelectric properties

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Acknowledgements

This project was supported by the National Natural Science Foundation of China (Grant Nos. 50666001, 50802101).

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2014 Higher Education Press and Springer-Verlag Berlin Heidelberg